An investigation on economy and CO2 emission of water alternating steam process (WASP) using response surface correlation

Abstract

In steamflooding, the steam tends to move toward the upper portion of the reservoir due to the gravitational effect causing poor drainage in the lower section. This causes the steam to breakthrough to the production well early. The water alternating steam process (WASP) often provides a solution to the problem. However, studies on WASP are found very limited despite the fact that this process is sensitive to the operating conditions. By investigating the WASP using response surface correlation, the factors governing steam injections operations are evaluated. To achieve the maximum net present value (NPV), several operating conditions are investigated. The side effect of gas fuel burning in the steam generation, i.e., CO2 emission, is considered in selecting the optimum operating condition. As illustrated by reservoir simulation results, if the economy is prioritized and oil price is 45 $/barrel, the optimum case is achieved in which the WASP-start is 3.0 years, the WASP-cycle is 3.5 months, and the steam/water injection rate is 141 m3/day. The resulting NPV is 14.1 MM$, and the CO2 emission is 28.53 × 103 tonnes.